You would be better off trying to find replacement key caps & scissors. I'm not sure if anyone has them yet. Plus you must be very careful when removing & attaching the keycaps since it is very easy to break the fragile clips on the keycaps & nubs on the scissor mechanisms.
FYI, in some regions you may be able to do an official self repair through Apple where Apple sends you the necessary parts.
Self Service Repair - Apple Support
I believe the Keycap Kit (ANSI) is 923-06088......I believe this is the US version and the Keycap Scissor Kit for the M-Series is 923-03863. Apple likes to use a special tool to remove the keycaps.....I personally don't care for it and go the old school method for removing keycaps, but a co-worker uses the Apple tool.
Also, you listed two different Axxxx series numbers. Only the A2992 matches with a MBPro 14" (M3 Pro/Max, Nov. 2023) model while the other partial A229 (missing a digit) does not match the M3 at all. The 661-35708 Keyboard Top Case Assembly is for the MBPro 14" (Nov. 2023) base model.....not the M3 Pro/Max CPU. You can get the exact model of your Mac by clicking the Apple menu and selecting "About This Mac".
FYI, to replace the Top Case/Keyboard Assembly requires removing every single internal part which is difficult & time consuming. It is a royal pain to remove & reinstall the Logic Boards due to all the cables that must be pulled out of the way which is very annoying & difficult on the M-series MBPros. There are a lot of chances to accidentally damage a cable or connector which could result in an even more expensive repair that you may not be able to perform due to Apple's parts pairing.